This invention relates to an arrangement of stock material, such as flat strip material arranged in coils, which is fed or uncoiled from the coils for a desired use application. In particular, the invention relates to flat strip metal arranged in coils for continuous feed of the material to a machine involved in a stamping process or a spring machine or other equipment requiring continuous supply of material for extended periods of time.
Still more particularly, the present invention relates to an arrangement wherein a plurality of large diameter flat coils of flat strip metal are stacked in substantially coaxial relationship and interconnected one with the other for continuous and uninterrupted feed of the flat strip material from the coils during a manufacturing process.
In accordance with one form of the invention, a plurality of coils are substantially coaxially arranged, with alternate coils wound in opposite directions and with the outside of a first coil connected to the outside of a second coil, and the inside of the second coil connected to the inside of a third coil, and so on throughout a plurality of coils containing any desired number of coils.
In another form of the invention, a plurality of coaxially arranged flat coils of strip material are arranged with the outside of a first coil wound into the inside of a second coil, and with the transition from the outside of the first coil to the inside of the second coil passing through a spacer positioned between the coils.
In a third form of the invention, a plurality of flat coils of strip material are arranged with the outside of a first coil wound into the inside of a second coil, and with the strip of material extending from the outside of the first coil to the inside of the second coil lying flat against the first coil and sandwiched between the first and second coils.
In many manufacturing processes, such as in spring machines or stamping processes and the like, a relatively continuous supply of strip material is required for extended periods of time. In the prior art, flat coils of stock are provided for supplying the material to such machines and the like, and since the maximum diameter of the coils is limited due to space requirements and ease of handling and the like, the length of time which the stock can be continuously fed to the machines is accordingly limited. Thus, with prior art apparatus, each time a single coil is depleted, the machine must be shut down and another coil supported on a payoff or payout stand and the strip of material threaded to the machine. This requires a downtime of the machine of about 10%, with resultant loss in production and increased costs to the manufacturer and thus the consumer. One attempt in the prior art to solve the above problems involved the provision of a transverse wound coil comprised of a strip of material wound upon a spool in the manner of line wound upon a fishing reel, whereby a continuous supply of material equal to several of the usual flat coils could be provided for continuous feed to a machine. While this arrangement is satisfactory for some materials, such as rods or string or wire or the like, it has not proven satisfactory for use with flat strip materials, since the material tends to become caught or overlapped, thus stopping feed of the material and interrupting production.
With the present invention, however, a plurality of coils can be formed from a continuous strip of material, wound continuously from one coil to the next, or if desired, separate coils can be quickly and easily manufactured in a conventional manner with existing equipment and the ends of adjacent coils spliced together. In either event, the coils can then be stacked one upon the other for continuous feed from the coils in successive order without requiring downtime of the machine for rethreading of a new supply of stock, as is required in the prior art. Also, with the unique interconnection of the plurality of stacked coils according to the invention, the problem of jamming or interruption of feed of the stock from the coils is eliminated. Moreover, whereas with conventional single flat coils the amount of material which may be continuously supplied to the machine is limited due to the maximum diameter of the coils, and whereas in traverse wound coils the maximum thickness of the coils is limited due to practical considerations, in accordance with the present invention as many coils may be stacked one upon the other as desired for continuous feed for a desired period of time. Further, with coils connected according to the invention, binding straps on the coils can be eliminated, and in fact the coils need not be confined for proper operation. Still further, coils wound according to the invention are less costly and more simple to make than prior art arrangements, and are lighter in weight. Additionally, in some forms of the invention, including the preferred form, there is no distortion of stock going from one coil to another, and in the preferred form, spacers are not required between adjacent coils. Also, any welds or splices between lengths of the strip material can be appropriately marked for easy identification and removal after processing.